The pursuit of higher efficiency and lower cost is a constant theme in the field of light-absorbing optoelectronic devices such as photodetectors and photovoltaics. Among various approaches to enhance efficiency and reduce cost, plasmonic structures have generated interest.
A plasmon-optoelectronic system can be categorized by two main parts, a plasmonic component and an optoelectronic device component, and various combinations of the two have been studied. For the plasmonic component, structures previously explored include sputtered, evaporated, or annealed metal islands, and e-beam or focused ion-beam lithographically patterned nanoantennas. The control over the spectral position and line width of the plasmon resonance increases with each method, but the cost of e-beam or focused ion-beam lithography is significantly higher and not practical for large-scale production (optical lithography is also used for plasmonic components but the application is constrained to infrared wavelength range).
For the light-absorbing optoelectronic device component, several materials and structures have been explored, including bulk and epitaxially grown thin-film semiconductors, p-n junction diodes, and organic photovoltaics.
Color-selective detection is desirable in many imaging applications, which may include a photoabsorbing device. Currently, such a function is primarily realized with charge-coupled devices (CCD) or complementary metal-oxide-semiconductor (CMOS) sensors, both of which rely on iterating optical lithography steps and associated doping and etching processes to manufacture. What is desired, therefore, are improvements in the performance and manufacturing efficiency of color-selective photoabsorbing devices.